一种新的HBT小信号模型参数优化提取法

阐述了一种新的异质结双极型晶体管（HBT）的小信号模型参数提取方法――综合多偏置点优化参数提取法. 对HBT小信号模型进行推导并确定外部参数和内部参数的计算公式;介绍了多偏置点优化算法,并在GaInP/ GaAs HBT器件上进行了鲁棒性和精确性测试. 实验采用了一系列随机初始值,结果表明提取的参数值具有唯一收敛性和精确性,仿真结果与测量数据的相对误差小于1%.     

Direct parameter-extraction method for HBT small-signal model

An accurate and broadband method for the direct extraction of heterojunction bipolar transistor (HBT) small-signal model parameters is presented in this paper. This method differs from previous ones by extracting the equivalent-circuit parameters without using special test structures or global numerical optimization techniques. The main advantage of this method is that a unique and physically meaningful set of intrinsic parameters is extracted from the measured S-parameters for the whole frequency range of operation. The extraction procedure uses a set of closed-form expressions derived without any approximation. An equivalent circuit for the HBT under a forward-bias condition is proposed for extraction of access resistances and parasitic inductances. An experimental validation on a GaInP/GaAs HBT device with a 2×25 μm emitter was carried out, and excellent results were obtained up to 30 GHz. The calculated data-fitting residual error for three different bias points over 1-30 GHz was less then 2%     

A pure analytic method for direct extraction of collector-up HBT's small-signal parameters

A pure analytic procedure for direct extraction of the small-signal equivalent-circuit parameters, including extrinsic inductances, has been demonstrated and successfully applied to III-V and SiGe collector-up heterojunction bipolar transistors (HBTs). This method can alleviate some difficulties encountered among conventional extracting techniques that are the use of additional test structures, forward-biased measurements at specific bias conditions, and empirical optimization process. In this paper, the hybrid-/spl pi/ equivalent-circuit elements are extracted in a simple and efficient way from impedance and admittance formulation on the basis of measured S-parameters. To study the bias dependence, the extrinsic and intrinsic circuit components are evaluated under different bias conditions. The model parameters are sequentially derived during the extraction process yielding a full set of physical element values. The validity of our model is explored on pnp collector-up AlGaAs-InGaAs HBTs, and a good coincidence between measured and modeled S-parameters is observed for the entire frequency range of operation. Consistent extracted trends indicate that this improved equivalent-circuit model is suitable to be implemented in circuit simulators for microwave-circuit TCAD applications.     

改进萤火虫算法在Okumura-Hata模型修正中的应用

针对Okumura-Hata模型在不同区域对电波传播衰减的预测与实测难以匹配的问题,提出了一种Okumura-Hata模型修正方法.提取Okumura-Hata模型的各参数作为带约束条件的优化变量,以预测值与实测值的均方根误差和平均误差的加权和构造适应度函数,运用萤火虫算法进行优化实现Okumura-Hata模型在西安市区的本地化.在萤火虫算法中引入了“基因突变”和“优胜劣汰”操作,形成了一种改进型算法.基于大量实测数据的模型修正结果表明,所提方法可使电波损耗的预测值与实测值的均方根误差达到理论最小值9.585 9 dB,具有可行性.与基本萤火虫算法相比,改进的算法全局搜索能力更强,收敛速度更快.     

Fast and efficient extraction of HBT model parameters usingmultibias S-parameter sets

Accurate parameter extraction technique has been presented for a small-signal equivalent circuit model of AlGaAs-GaAs HBT's. This technique makes use of multibias data optimization regarding two sets of S-parameters in the active mode and one in the cut-off mode, under the physics-based constraint that current-dependent elements in two active bias circuits are linked to each other by the ratio of their currents. This multibias optimization as well as the constraint imposed on intrinsic parameters may reduce the degree of freedom of circuit variables and increase the probability of finding a global minimum result. As a result of this extraction, good agreement is seen between the circuit models and their measured S-parameters in the frequency range of 0.045 to 26.5 GHz     

Direct extraction of an empirical temperature-dependent InGaP/GaAs HBT large-signal model

A new empirical InGaP/GaAs heterojunction bipolar transistor (HBT) large-signal model including self-heating effects is presented. The model accounts for the inherent temperature dependence of the device characteristics due to ambient-temperature variation as well as self-heating. The model is accompanied by a simple extraction process, which requires only dc current-voltage (I-V) and multibias-point small-signal S-parameter measurements. All the current-source model parameters, including the self-heating parameters, are directly extracted from measured forward I-V data at different ambient temperatures. The distributed base-collector capacitance and base resistance are extracted from measured S-parameters using a new technique. The extraction procedure is fast, accurate, and inherently minimizes the average squared-error between measured and modeled data, thereby eliminating the need for further optimization following parameter extraction. This modeling methodology is successfully applied to predict the dc, small-signal S-parameter, and output fundamental and harmonic power characteristics of an InGaP/GaAs HBT, over a wide range of temperatures.     

RF Small-Signal Analysis of Schottky-Barrier p-MOSFET

This paper presents a detailed RF study for source/drain Schottky-barrier (SB) MOSFETs. Using on-wafer -parameters, high-frequency (HF) figures-of-merit (FoMs) and small-signal equivalent circuits (SSEC) are first extracted and discussed for a -gate-length SB MOSFET. Then, using ac simulations, HF FoM's sensitivity along SB height and underlap length variations are subsequently presented. The whole study provides, for SB MOSFETs, a deep understanding of key ac-element (transconductances and capacitances) behavior as well as process-parameter optimization to achieve the best HF FoMs.     

太赫兹平面肖特基二极管参数模型

根据太赫兹平面肖特基二极管物理结构,在理想二极管SPICE参数模型的基础上建立了二极管小信号等效电路模型。依据该二极管等效电路模型设计了基于共面波导（CPW）去嵌方法的二极管S参数在片测试结构,并对其在0.1~50 GHz、75~110 GHz频率范围内进行了高频小信号测试,利用测试结果提取了高频下二极管电路模型中各部分电容、电阻以及电感参数。将相应的高频下电容与电阻参数分别与低频经验公式电容值和直流I-V测试提取的电阻值进行了对比,并利用仿真手段对高频参数模型进行了验证。完整的参数模型以及测试手段相较于理想二极管SPICE模型和传统的参数提取方法可以更为准确地表征器件在高频下的工作状态。该建模思路可用于太赫兹频段非线性电路的优化设计。     

An approach to determine small-signal model parameters for InP-based heterojunction bipolar transistors

A new method for the extraction of the small-signal model parameters of InP-based heterojunction bipolar transistors (HBT) is proposed. The approach is based on the combination of the analytical and optimization technology. The initial values of the parasitic pad capacitances are extracted by using a set of closed-form expressions derived from cutoff mode S-parameters without any test structure, and the intrinsic elements determined by using the analytical method are described as functions of the parasitic elements. An advanced design system is then used to optimize only the parasitic parameters with very small dispersion of initial values. Good agreement is obtained between simulated and measured results for an InP HBT with 5/spl times/5 /spl mu/m/sup 2/ emitter area over a wide range of bias points up to 40 GHz.     

Very high-frequency small-signal equivalent circuit for shortgate-length InP HEMTs

A small-signal equivalent circuit for short gate-length InP high electron-mobility transistors (HEMTs) operating at very high frequency (HF) is proposed. First, the extrinsic parameters of the equivalent circuit are determined using a cold HEMT, but without forward gate bias. Then the intrinsic parameters of the equivalent circuit are extracted, including the frequency dependence of some of them. A fast and accurate method based on least-squares regressions is presented to obtain the extrinsic and intrinsic parameters from measured S-parameters. The improved equivalent circuit accurately fits the S-parameters of 0.25-μm InP HEMTs over the 500-MHz up to 40-GHz measurement bandwidth, for all gate-to-source and drain-to-source voltages     

基于MOS Model 20的RF-SOI LDMOS大信号建模

提出了一种新的基于Philips MOS Model 20 (MM20) 的RF-SOI (radio frequency silicon-on-insulator) LDMOS (laterally diffused MOS) 大信号等效电路模型. 描述了弱雪崩效应以及由热效应引起的功率耗散现象. 射频寄生元件由实验测得的S参数解析提取,并通过必要的优化快速准确地获得最终值. 模型的有效性是通过一20栅指 (每指栅长L=1μm,宽W=50μm) 体接触高阻RF-SOI LDMOS在直流,交流小信号和大信号条件下的实验数据验证的. 结果表明,直流、S参数 (10MHz~20.01GHz) 以及功率特性的仿真和实验测得数据能够很好地拟合,说明本文提出的模型具有良好和可靠的精度. 本文完成了对MM20在RF-SOI LDMOS大信号应用领域的拓展. 模型由Verilog-A描述,使用ADS (hpeesofsim)电路仿真器.     

Optimal parameter extraction and uncertainty estimation in intrinsic FET small-signal models

Analytical expressions for the relative sensitivities in the parameters of a standard intrinsic FET small-signal model with respect to deviations in the measured S-parameters are derived. This enables, in combination with a measurement uncertainty model, the model parameter uncertainties to be studied versus frequency. As a result, optimal, minimum uncertainty, parameter extraction can be performed independent of the bias voltage and without prior knowledge about the device frequency behavior, thus making it suitable for implementation in automatic multibias extraction programs. The derived sensitivities are furthermore used to analytically calculate the uncertainty in the S-parameter response of the extracted model in terms of the uncertainties in either the parameters or the measurement it was extracted from.     

RF Amplifier Design with Large-Signal S-Parameters

High-power UHF transistors have been characterized through the use of large-signal S-parameters. These S-parameters have been used successfully to design UHF power amplifiers. Waveform measurements show that due to the Q of the package parasitic, most class C operated UHF power transistors have nearly sinusoidal waveforms at their package terminals. Experimental evidence presented shows that the large-signal S-parameters are relatively independent of power once the device is turned on. These two observations make it possible to extend modified small-signal S-parameter design techniques to large-signal power amplifiers.     

AlGaAs/GaAs HBT model estimation through the generalizedpencil-of-function method

An efficient technique of extracting the small-signal model parameters of the heterojunction bipolar transistor (HBT) is proposed in this paper. The relation between the extrinsic and intrinsic model parameters, which can be employed to drastically reduce the search space, is studied in depth. For the first time, the HBT transistor is characterized by describing S-parameters with a set of complex exponentials using the generalized pencil-of-function method. The reliable initial values of some extrinsic elements can be determined from the set of complex exponentials. This novel approach can yield a good fit between measured and simulated S-parameters     

AlGaN/GaN高电子迁移率晶体管小信号等效电路的参数提取

本文在高电子迁移率晶体管(HEMT)小信号等效电路模型的基础上,考虑了AlGaN/GaN HEMT的结构特性,具体分析了寄生参数和本征参数的提取方法.采用这些方法,实际测量了5～10 GHz频率下HEMT器件的小信号S参数并提取了它的电学参数,S参数的计算值与实际测量值进行了比较.实验结果表明此方法简单易行,较为精确.     

应用-种组合优化算法提取场效应管模型参数

提出一种将模拟退火法与基于主成份灵敏度分析的空间坐标变换相结合的优化算法，用以精确提取微波场效应管小信号等效电路参数。该法具有快速收敛，能够消去模型坏条件等优点，从而提高了低灵敏度元件Ｒｉ、Ｒｇ、Ｒｄ等的提取精度，使各个模型参数均能得到精确、快速提取。     

A semianalytical parameter extraction of a SPICE BSIM3v3 for RFMOSFET's using S-parameters

In this paper, we present a new parameter-extraction method combining analytical and optimization approaches for the RF large-signal Berkeley Short-Channel IGFET Model 3, Version 3.0. Using S-parameters of MOSFET's with different channel lengths and widths at zero gate bias, all overlap capacitances are accurately determined in the high-frequency range. The junction-capacitance model parameters are extracted using S-parameters of devices with different perimeter-to-area ratios at two different biases of zero and high voltages. A robust technique utilizing simple Z-parameter equations is also used to extract resistances (R_g and R_d) and inductances. The source and substrate resistances are initially determined using the zero-bias optimization, and their uncertainties are subsequently eliminated in the normal-bias optimization. Good agreements between measured and modeled S-parameters from 0.5 to 12 GHz demonstrate the validity of this semianalytical method     

A new parameter extraction technique for small-signal equivalentcircuit of polysilicon emitter bipolar transistors

We propose a new parameter extraction method for advanced polysilicon emitter bipolar transistors. This method is based on the predetermination of equivalent circuit parameters using the analytical expressions of de-embedded Z-parameters of these devices. These parameter values are used as initial values for the parameter extraction process using optimization. The entire device equivalent circuit, containing RF probe pad and interconnection circuit parameters extracted by test structures, is optimized to fit measured S-parameters for eliminating de-embedding errors due to the imperfection of pad and interconnection test structures. The equivalent circuit determined by this method shows excellent agreement with the measured S-parameters from 0.1 to 26.5 GHz     

Localization Optimization in WSNs Using Meta-Heuristics Optimization Algorithms: A Survey

In Wireless Sensor Networks, node localization is one of the most important system parameters. Determining the exact position of nodes in these networks is one of vital and tedious tasks. This paper presents a review of the most localization methods which optimize the localization error. It provides a new taxonomy of techniques used in this field, including Mobile Anchor, Machine Learning, Matematical Models and Meta-heuristics. In this later, we survey its different algorithms such as Genetic Algorithm, Particle Swarm optimization, Ant Colony Optimization, BAT optimization algorithm, Firefly Optimization Algorithm, Flower Pollination Algorithm, Grey Wolf Optimization algorithm, Artificial Bees Colony Optimization Algorithm, Fish Swarm Optimization Algorithm and others. Further, the comparison between these metaheuristics algorithms based localization optimization is done. Finally, a comprehensive discussion of the performance parameters such as accuracy, convergence rate, energy consumption and the number of localized nodes is given.

     

A new pinched-off cold-FET method to determine parasiticcapacitances of FET equivalent circuits

A new pinched-off cold FET method to extract the parasitic capacitances of FETs is proposed in this paper. The method is based on a physically meaningful depletion-layer model and the theoretical analysis of the two-port network for the pinched-off cold FETs. The parasitic gate capacitance (C_pg) and the parasitic drain capacitance (C _pd) of FETs are extracted using the linear regression technique associated with the frequency responses of Y-parameters. The extraction method can be applied to the small-signal equivalent-circuit modeling of the FETs including MESFETs, heterojunction FETs, and high-electron-mobility transistors. According to the new analytical method, the simulated S-parameters exhibit great agreement with the measured S-parameters for the equivalent-circuit models of FETs